The invention relates to a composite material, comprising a thermoplastic resin and a glass fiber fabric, used for the fabrication of a structural member. Such a member can comprise a portion of or the entirety of any structural unit. Preferably the member can be used in the manufacture, reconstruction or repair of fenestration units such as windows or doors for residential and commercial architecture. More particularly, the invention relates to an improved composite material adapted to extrusion processing, and formed into structural members that have improved properties when used in windows and doors. The composite materials of the invention can be made to manufacture structural components such as tubes, rails, jambs, stiles, sills, tracks, siding, stop and sash, pipe, I-beams, H-beams, bar stock, angles, channels, tees, tubing, rods, zees, sheet stock plates, etc., nonstructural trim elements such as grid, cove, bead, quarter round, repair pieces, grills, etc.
Structural materials have been made from composites comprising a resin and a reinforcing material such as a fiber, thread, yarn, roving, fabric or other such fibrous material. Such reinforcement materials have been used in a variety of applications. Conventional window and door manufacturers have commonly used wood and metal components in forming structural members. Commonly, residential windows are manufactured from milled wooden members, glass, screening fabric or extruded aluminum parts that are assembled to form typically double hung or casement units. Conventional glass-wooden windows while structurally sound, useful and well adapted for use in many residential installations, can deteriorate under certain circumstances. Conventional wood windows can also require painting and other periodic maintenance. Wooden and aluminum windows also suffer from cost problems related to the availability of suitable material for construction. Clear wood products are slowly becoming more scarce and are becoming more expensive as demand increases. Metal components are often combined with glass and formed into single unit sliding windows. Metal windows typically suffer from substantial energy loss during winter and summer months. Metal (Aluminum and ferrous metals), thermoplastic and wood materials can suffer from deterioration, (i.e.) rust, rot, photochemical deterioration, etc.
Extruded thermoplastic materials have also been used as non-structural components in window and door manufacture. Filled and unfilled thermoplastics have been extruded into useful seals, trim, weather-stripping, coatings and other window construction components. Thermoplastic materials such as polyvinyl chloride have been combined with wood members in manufacturing PERMASHIELD(copyright) brand windows manufactured by Andersen Corporation for many years. The technology disclosed in Zanini, U.S. Pat. Nos. 2,926,729 and 3,432,883, have been utilized in the manufacturing of plastic coatings or envelopes on wood or other structural members. Generally, the cladding or coating technology used in making PERMASHIELD(copyright) windows involves extruding a thin polyvinyl chloride coating or envelope surrounding a wood structural member.
Polyvinyl chloride has been combined with wood fiber to make extruded materials. Such materials have successfully been used in the form of a structural member that is a direct replacement for wood. These extruded materials have sufficient modulus, compressive strength, coefficient of thermal expansion to match wood to produce a direct replacement material. Typical composite materials have achieved a modulus greater than about 500,000 psi, an acceptable CTE, tensile strength, compressive strength, etc. to be useful. Deaner et al., U.S. Pat. Nos. 5,406,768 and 5,441,801, U.S. Ser. Nos. 08/224,396, 08/224,399, 08/326,472, 08/326,479, 08/326,480, 08/372,101 and 08/326,481 disclose a PVC/wood fiber composite that can be used as a high strength material in a structural member. This PVC/wood fiber composite has utility in many window and door applications.
Kirk-Othmer Encyclopedia of Chemical Technology and other such basic references contain a large proportion of information on the formation of composite materials which are defined as combinations of two or more materials present as separate phases combined to form desired structures. Typically, composites have fiber in some form combined with a continuous resin phase.
Oliveira, U.S. Pat. No. 4,110,510 teaches a PVC impregnated mesh having barium sulfate coated chlorinated polyethylene laminated to a sound deadening foam material.
Dost et al., U.S. Pat. No. 4,464,432 discloses a process for manufacturing porous textile substrates and teaches a impregnated substrate comprising fabric and a gelled thermoplastic under pressure to impregnate the fabric.
Schock et al., U.S. Pat. No. 4,492,063 discloses extruded plastic materials having glass fiber reinforced portions including fiberglass mat or fabric.
Bafford et al., U.S. Pat. No. 4,746,565 discloses a flame barrier comprising a face fabric laminated with a glass fabric coated with an encapsulated coating.
Wahl et al., U.S. Pat. No. 4,885,205 discloses a fiberglass mat or fabric impregnated with thermoplastic that is roughened or pretreated with a needle.
Amotta, U.S. Pat. No. 5,045,377 discloses a composite grid comprising a thermoplastic material is a grid format. The grid components can be reinforced with fiberglass yarn.
Laminates manufactured by interlayering fiber mat or glass fiber fabric with sheet-like thermoplastic materials have been known. The interlayered structures are often exposed to elevated temperatures and pressures to form a mechanically stable laminate structure.
The combination of a fiberglass mat or fabric with thermosetting components are disclosed in Biefeld, U.S. Pat. No. 2,763,573 and Daray, U.S. Pat. No. 5,455,090 and Fennebresque et al., U.S. Pat. No. 2,830,925.
A substantial and continuing need exists to provide a improved composite material (using resins or polymers comprising vinyl chloride and polymers having no chloride containing monomer components) that can be made of thermoplastic resin or polymer and a reinforcing fiber component. A further need exists for a composite material that can be extruded into a shape that is a direct substitute for the equivalent structural member milled shape in a wood or metal structural member. A thermoplastic resin having fiber or fabric compatibility, good thermal properties and good structural or mechanical properties is required. This need also requires a composite with a coefficient of thermal expansion that approximates wood, that can be extruded into reproducible stable dimensions, a high modulus, a high tensile strength, a high compressive strength, a low thermal transmission rate, an improved resistance to insect attack and rot while in use and a hardness and rigidity that permits sawing, milling, and-fastening (nail, screw, staple or glue) retention comparable to wood members.
We have found that the problems relating to forming a structural member or cooperative structural member or a substitute for wood or metal structural members can be solved by forming a thermoplastic resin/glass fabric composite material into a shaped structural member. A large variety of resins have been provided over the last few years. These resins are available in a variety of grades, molecular weights, melting points, formulations, containing materials of great variability. We have found that not every thermoplastic resin is useful in the manufacture of glass fabric composites. The resin must be compatible in the melt form with glass fabric to form a high strength composite. The glass fabric must be fully wetted and penetrated, in its woven structure, with the thermoplastic to form a high strength composite material. Further, the thermoplastic resin must have thermal properties (melt flow properties or mp less than 210xc2x0 C.) that permit successful composite manufacture. Lastly, the resin fiber fabric composite should have high temperature stability and should provide sufficient structural properties to the composite material to be successful in structural application within a range of typical temperatures. Even in bright direct sunlight a dark pigmented unit should not lose the profile shape or related properties.
We have also found that the successful manufacture of structural members for windows and doors requires the preliminary shaping of the glass fabric into a preformed shape conforming to an extrusion die used in forming the profile. Combining the preformed fabric and resin in the die results in the intimate contact of the resin with the fabric. We have further found that modifying the edges of the fabric, when each edge is exposed to resin under pressure results in an improved materials. We have found that introducing a fold or overlap modification into the edge stabilizes and strengthens the edge and prevents fraying or other edge deterioration. We have found that the intimate mixing of the resin, fiberglass fabric results in a product that is uniquely adapted to the extrusion manufacture of resin/fabric components and achieves the manufacture of a useful structural member replacement product. For the purpose of this patent application, the term xe2x80x9cshapexe2x80x9d indicates that the flat (planar) sheet-like glass fabric is changed from the planar structure from the take off roll, into a non-planar structure. Such non-planar structures can include the introduction of an angle from one fabric surface to another that can range from about 0xc2x0 or 1xc2x0 through a 180xc2x0 to a 360xc2x0 angle. An angle of about 0xc2x0 or about 360xc2x0 indicates a fold where the glass fiber is folded back on the adjacent fabric. Additional common angles include 45xc2x0 angles, 90xc2x0 angles, 135xc2x0 angles, 180xc2x0 angles, 270xc2x0 angles, etc. Further, the shape can include smooth curves such as substantially curved surfaces, a relatively small curved surface included with a substantially planar surface, a rolled edge, a wholly included circular shape introduced into the extruded part, etc. The shape can also include relatively complex profiles having one or more angles, one or more curved surfaces, one or more folded or rolled edges, or more areas where the fabric is folded back and doubled up with two or more folds, at an edge or at an interior location. Further, other closed surfaces can be formed in the extrusion of the fabric. For example, a circular, oval, square, rectangular or triangular shape can be introduced into the folded glass fabric, covered with rigid or semi-rigid polyvinyl chloride resulting in a desired enclosed shape or profile. The purpose of introducing a particular shape or profile into the glass fiber is to conform the glass fiber to an extrusion die wherein the glass fiber is incorporated with thermoplastic resulting in a desired profile shape that can be used in a fenestration, window or door unit. The extruded material can contain one, two or more glass fabric sheets and can contain other fabrics such as metal, Kevlar(copyright), nylon, etc.